Steering mechanism for vehicles



1,6v 4 0 June 14, 1927. o. F WARHUS 32, 6

STEERING MEGHANISM FOR VEHICLES Filed April 17. 1925 2 sheets-snm 2 @4, y ff ,www v Q l: f /j ff/4 f if? J3 34 3 V J5 27 I# d OR INVENT ATTORNEY;

Patented June 14, 1927.

renate OLIVER F. WAlEtI-IUS,

aLBAivY, new YORK, Assrcavoa To vnnsann conrnarioiv,

A conronarion or New YORK.

STEERING MECHANSM FOR VEHICLES.

Application filed April 17, 19,25.

This invention relates to steering mechanism for motor driven vehicles ot that type in which the body is pivotally mounted on one or more trucks or bogies. The steering ot such vehicles presents various ditiiculties especially inthe case ot those of considerable length. In my prior Patent No. 1,599,- 152 there is disclosed an improved type o steering mechanism tor vehicles of the above mentioned character, the purpose ot' which is to overcome some ot these difculties and permit more accurate steering and better control of vthe vehicle.

rlfhe main object ot the present invention is to provide additional improvements especially adapted for use in conjunction with steering mechanism ot' the general type disclosed in the aforesaid application which will insure even better control and more accura esteering oit the vehicle.

In a vehicle ot' the type disclosed in the above mentioned patent, the operator located within vthe body cannot tell accurately the extent to which the front truck has been turned to one side or the other under the body.l By turning,n thesteering wheel, the front wheels of the front truck are turned angularly, and then as the vehicle proceeds, the truck swivels to an angular position determined by the angular position to which the trontwheels have beenturned, the front wheels being; reversely turned during,` the swiveling action ot the truck until, in the iinal angular position ot' the truck, the front wheels are in substantial parallelism with the rear wheels and with the truck frame. lt' the operator turns the steering wheel 'further in thesame direction, this same action takes place and if continued tar enough the truck would be caused to.' swivel around to the maximum position to'which it is desired to have it turned.` lt is common to provide a stop which will prevent any outside orces, such as slridding tendenciesv from swiveling' the'truclr beyend this point. lf the parts are in this maximum relation and the operator, not knowing that themaximum relation has been reached,turns the steeringwheel still further. sol to given further turning movement to the front wheels :of the truck, then as'the `vehicle proceedsY in its forward movement andY asthe truck cannot swivel inrtheij'the rontwheels of the truck will slide overtljie ground Vreason of their 11er relaties@ the wel; eilf @essere Serial No. 23,794.

wear on the tires of those wheels will occur. lu accordance with this invention, means are provided tor guarding against such excessive wear occasioned in thismanner. To that end means vare provided which serve to limit turning` movement ot the steering wheel more than that amount which will bring the truck to its predetermined maximum angular position. f A i lfhe stop 'for limiting the swiveling action of the bogietruck might be omitted as the above mentioned `device tor limiting the turn ing' movement of the steering wheel can be so arranged as to preventfurther lturning ot the steering wheel after the truck has swiveled to a predetermined angular position regardless of whether its swiveling action beyond this predetermined position is posi-` tively arrestcd by a stop, However, such an arrangement is not productive of the best results and it is desirable to have not only devices 'for limiting the turning` movement ot the steering wheel, but alsoia stop for limiting` the swivelingaction oit' the bogie all arranged so that there is a deiinitecoordina tion ot'action whereby the steering wheel cannot be turned further than that amount which will bring the bogie into contact with the stop that limits its swiveling action.

The accompanying drawings illustrate the preferred embodiment oit the invention in combination with steering mechanism ot the general type disclosed in the above mentioned copending application. i 1n the drawings, Fig. l is a side elevation partly in section ot the forward end of the chassis showing the improved steering` mechanism'applied to thetorward truck; Fig. 2 is a bottom plan View of the forward truck and body frame showing;l the position as-j sinnedl by the truck relativev to 'the body trame after it has made its maximum swiveling movement.; Fig. Sis a bottom planview ot' the tront wheels ofthe' forward truck showing; certain portions of thel steering mechanism associated therewith; Fig.` lis aplan view jot 'a portion ot the truck frame and eertain parts of the steering mechanism which aie'asso'ciated i witli V"the, body trams f5 avertlicalsection ofthe steerli mechallsiu l`The body trame of the vehicle is represent-d atfl they trame otfthefforward tlil ishshgown 'vat 2.A The truck in'thepresent insane 'is presentati' ai par" niet CTI the center of the wheel to the point about wheels 3 and a pair of l'ront wheels 4. The body frame is pivotally mounted on the truck lrame by meansl of a. king pin construction comprising a casting 5 secured to the body frame, a king pin casting 6 secured to the casting 5, and the king pin proper 7 formed on the casting G (Fig. 5). The king pin 7 is mounted to turn in a socket 8 mounted on the truck frame 2. The vertical load oi the body supported by roller bearings 9 associated with the trucl: fra-me and which are in rolling contact with Vone oit' thel lower faces 10 of the casting.

The roller bearings 9 constitute in effect a fifth wheel by means ot which the body frame is supported on the truck.

A steering post 11, which may be actuated by means of the usual steering wheel on the vehicle, is provided on its lower end with a bevel pinion 12 (Fig. Ll) which meshes with a corresponding bevel pinion 18 mount-- ed on a horizontal shaft lll. The shaft 14 carries a worm 15 meshing` with a worm wheel 16 and is keyed to a vertical shaft 17 extending axially through and journalled in the king pin. rFor this purpose the king pin is made hollow as shown in the drawings. The gearing 15, 1G may be located in the hollow casting 6 andv is preferably enclosed by a casing 18v which may be lilled with lubricant. The lower end of the shaft 17 has secured thereto an arm 19 which projects forwardly and which is pivotally connected at its iorward end to a telescopic tongue 20.

Y The tongue 2O extends rearwardly from its point ot connection with the arm 19 and vis operatively connected with a spindle 21 ro tatably mounted on the truck frame. A rotatable member 22 is rigidly secured to the spindle 21. rllhertransvers'e beam or axle 28 on which the front wheels are pivoted constitutes a convenient support for the spindle 21 and the rotatable member 22, a suit-able bracket 211 being provided for attaching these parts to the axle and for furnishing the necessary mounting for the rotating parts. The front wheels 4: of the truck are mounted to turn about substantially vertical axes 25 located at the extremities oi' the axle 23. Each wheel is provided with the usual steering arm 26. The arms 26 are pivotally connected by means of rods 27 to the ro; tatable member 22. Each rod 27 is connected to the rotatable member 22 on the far side of the center line ot the member as shown in F 2 and 3. By this arrangement whenever the rotatable member 22 is turned about its axis the front wheels are deflected or turned about their vertical axes differential or unequal amounts so that for any given turning radius each front wheel is substantially at right angles to a radius dra-wn from which the trucl: travels as a center. Then r Vthe steering wheel 011 the vehioleis actuated,

rotation is imparted' tothe shaft 17 through the gearing 12, 13, 15 and 16. This swings the arm 19 in a horizontal plane and also swings the tongue 2O about the axis of the spindle 21 thereby rotating this spindle and the member 22. The rotation of the member 22 causes the front wheels d to turn about their vertical axes to steer the front truck. The axis oi" the spindle 21 is located in advance of the az-:is of the shalt 17. 1n the normal position ot' the parts the arm 19 lies directly over and in parallelism with the tongue 20, the axis ot the spindle 21 then lying directly under the arm 19. However, when the arm 19 is moved to one side or the other as shown in Fig. 3, the arm 19 moves away from its position directly over the axis of the spindle 21. The front wheels now having been turned, the forward mot-ion oiE the vehicle will cause the front truck to swivel relatively to the body frame. As the truck thus swivels, the axis of the spindle 21, being on the truck frame, will move back toward a position directly under the arm 19. This will cause the front wheel to turn back toward their original position in alignment with the rear wheels, and when this condition occurs the truck will cease its swiveling movement with respect to the body frame and the axis ot the spindle 21 will tend to remain directly under the arm 19. The longitud-inal axis of the truck frame will then be at an angle with respect to the longitudinal axis oi the body frame and all four wieels of the truck will be in alignment. 1'1" it is desired to steer the front wheels still further in the same direction7 or it it is desired to steer them in the reverse direction, the steering wheel is further actuated to swing the arm 19 in the proper direction and then the trucl; will again swivel relatively to the body frame until the axis of the spindle 21 again moves under the arm 19 when the swiveling action of the truc-lt will again cease with the front and rear wheels et the truck in alignment.

@ne function of the steering mechanism described above is to prevent unintentional swiveling ot the truck under the vehicle body. ldlithout some arrangementsuch as described, the truck would have a tendency to continue swiveling with respect to the body trame.' This would render control of the vehicle diilicult because the operator is not always aware of the exact angular position of the truck lunder the body and he may turn the front wheels too far or may neglect to turn them back in time to prevent excessive swiveling action of the truck. This is especially true in vehicles of considerable length in which there is a lag between the turning movement of the' front wheels and the resulting lateral movement of the forward end of the body. However, with an arrangement such as described above for any given actuation ot' the steering wheel, the

iront wheels ot the truck will straighten up as the truck swivels relatively to the body trame.

It is customary to provide stops. such as those shown at and 31 to prevent further swiveling movement ot the truck in eithei direction when it has reached the maximum position to which it is desired to have it turned. Figure 2 shows the truck in its maximum angular rela-tion with respect to the body and in this position agportion ot the truck trame abuts against the stop 30 to prevent further swiveling of the truck in the same direction. li the truck were inthe reverse maximum angular position with respect to the body the truck frame would abut against the other stop 81.

lVhen the truck is in the position shown in Figure 2 or the corresponding reverse position, any further turning of the front wheels such as would tend to cau-se the truth to swivelA further in the same direction would have no effect in accomplishingthis, due to the tact that any further swiveling action of the truck in the same direction is positively prevented. Under these conditions the additional turning of the front Wheels would cause them to slide ovei the ground as the vehicle proceeds in its torward movement except 'for the swinging movement oi the rear end of the body and even so such slippage of the front wheels would occur itt they were turned an excessive amount, this being due to the fact that the front truck cannot respond by swiveling further with respect to the body. The means now to be described prevents or minimizes such slippage. In its preferred form this means includes a pin 28 preferably mounted immediately above the worm wheel 16. The cover of the casing 18 constitutes a convenient part on which to mount this pin. The upper tace ot the worm wheel 16 has secured thereto two abutments 29 so located that when the worm Wheel 16V moves through a predetermined angle in either direction, the forward end of one of the abutments 29 will come into contact with the. pin 28 and thereby positively prevent further movement oi the worm wheel. 1t is therefore impossible to turn the steering wheel more than that amount which will swing the arm 19 to the angle shown in Fig. 2 or to the corresponding angle in the other direction. Figure 2 shows the arm 19 swung to its maximum position in one direction and for this position of the arm the truck will move to its maximum angular position against the. stop 30. As the truck swivels toits maximum angular position, the front wheels are reversely turned toward alignment vwith the rear wheels. Fig. 2 shows the front wheels par` allel with the bogie frame in theJ final angu` lar position of the truck. However, in practice the final swiveling movement ot the bogie never reversely turns the iront wheels the fact that the rear end of the vehicle in r' turning keeps the front wheels ofthe front truclr turned just enough to cause the front truck tov move in thearc of a circle having the saine center as the arc oi' the circle in which the rear truck'- inoves. The stops on the steering lmechanism and the stops 30 and are so positioned and corclated that when the vehicle is moving in the arc of a circle with the iront truck in its maximum angular position the front truck frame will beA in contact with one of the stops 30, 3l and the arm 19 will be limited by its stop mechanism but at this time the front wheels of the front truc-lr will still be slightly turned as above indicated. However, they are prevented `trom being turned beyond this position by the stop devices on the steering mechanism. Hence, undesirable slippage of the front wheels of the front truck is prevented.

in the foregoing description it vhas been stated, in eiiect, that the steering` gear stops are so located that when the bogie truck moves to its ipinal angular position against either the stop 30 or the stop 31 the front wheels ot thebogie truck cannot be turned further. This relation and coordination between the two sets oic stops may be stated in another way. The nal angular position to which it is desired to kbring the bogie truck is known for a given vehicle. The stops for the steering gear prevent turning of the front wheels more t-han that amount which will bring the bogie truck t-o a certain angular position. Therefore, it may be said that the stops tor the steering gear are so located that they, and not the stops 30 and 31, are the primary factors in preventing the bogie truclr from swiveling beyond leither of its predetermined maximum angular positions during the steering operation. Viewing the matter in this way it may be said that the stops 30 and 31 are so located that theI trame of the bogie truck will abut against one of these stops gently just as it reaches the maximum angular position determined by the position of one of the steering gear stops. It is true that while the parts are in this posit-ion the front wheels cannot be turned further and thereby produce a tendency to skid as pointed out above, but

this arrested condition oi" the steering gear may be considered as having been brought about tor the primary purpose of bringing the bogie truclto its predetermined maximum angular position in which position either the stop- 30 or the stop 51 then acts to prevent any outside. forces, such as skidding tendencies, from turning the truck beyond its angular position.

It may sometimes be desirable under awa special and unusual conditions to render thc mechanism 28, 29 inoperative or ineit'ective so that front wheels may be turned beyond the angular position normally permitted by the steering mechanism. For this purpose the pin 28 may be threaded as shown in Fig. 5 and the socket 32 in which the pin is mount ed may be likewise threaded so that when the pin is turned in the socket it will move longitudin ally therein. In order to turn the pin an arm 33 may be secured thereto which may be actuated by a rod BeteXtending to any suitable point ot control on the vehicle. By actuating the rod 34 the pin 28 may be shirted axially so thatV it will be raised out ot the path ot the abutments 29. Under these circumstances the front wheels of the trucl; may be turned further than the amount normally permitted by the mechanism when the pin 28 is eective to limit its action. A spring 35 may be employed to return the pin to its normal position in the path ot the abutments 29.

The rear end of the truck has not been illustrated in the drawings as the particular method oi' mounting the body on' the rear wheels of the vehicle forms no part or the present invention. It might be stated, however, that the rear end of the body may be pivotally mounted on a truck provided with :tour or more wheels and the front wheels of the rear truck may be steered by automatic mechanism ot the type disclosed vin several of my copending applications.

l claim f1. A vehicle comprising a body, a truck having front and rear wheels on which the forward portion of the body is pivotally mounted, steering mechanism for turning the front wheels of the truck, moans for preventing swivelingof. the truck beyond the position in which it occupies a predetermined maximum angular relation with respect to the body, mechanism operating during the swiveling of the'truck to reversely turn the front wheels toward alignment with th-e rear wheels and means cective when the truck is in its maximum angular relation with respect to the body to limitturning of the front wheels in the direction tending to cause the truck to swivel beyond said maximum angular position.

2. A vehicle comprising a body, a truck having front and rearrwheels on which the forward portion of the body is pivot-ally mounted, steering means i'or turning the. front wheels of the truck including mechanism for reversely turning the front wheels toward alignment with the rear wheels when the truck swivels relatively to the body, means to prevent `actuation of the steering means beyond an amount which will bring the truck to a predetermined angular position with respect to the body and means et ective` when the truckA reaches said predetei-mined angular position for preventing swiveling movement ot the truck beyond sai\r predetermined angular position.

In testimony whereof I aliix my signature.

OLlVER F. VARHUS. 

